This old discussion about render time and noise...

[BBB3]

Quick question: When working on my latest scene (http://bertrand-benoit.com/blog/emmas-place-v-ray/) I hit my old problem about renders becoming very slow when the scene reached a certain level of complexity. This was using BF/LC.
But then, I had the random idea of switching from the progressive to the bucket mode and, miracle, things appeared to be running faster again and I could render 2K stills in under three hours, including reasonably smooth DOF using the default settings. I only really hit problems with a few sharp bokehs from shiny objects in the distance, which came out very grainy.
Is there something to this or is it one of these things I'm just imagining?

[zeronove]

maybe this one?
https://forums.chaosgroup.com/forum/...-low-cpu-usage

[yavor.rubenov]

Hello,

So if I understand correctly - you got a very slow render with the progressive sampler on that scene and the bucket sampler worked faster?
The easiest thing would be if you could send the scene to our support so that we can try it here and find out why the different samplers give very different timings.

Apart from this - could you share some details about:
- Hardware - what CPUs did you use and did you use DR ?
- Max and V-Ray versions ?
- Is it possible that you are hitting a memory limit - progressive needs quite some more memory. If that happens and the OS start to swap to disk - rendering will be much slower.


Best regards,
Yavor

[Raven]

If it is default settings bucket has a higher noise threshold of 0.01 as apposed to progressives 0.005

[MANUEL_MOUSIOL]

I'm working on an animation with dof and the bright highlights (which make a beautiful bokeh shape btw) are not getting noiseless. Even with 100 subdivs and 0.005 noise level. Render times went up from 5-10 minutes to more than 30 Though.
am I doing something wrong?